Print NxN matrix From https://stackoverflow.com/questions/4328442/how-can-i-display-a-n-x-n-matrix-of-random-numbers-in-java
public void printGraph(double[][] array, int n) {
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
System.out.println(array[i][j]);
}
}
}